Doing this is toxic, especially if we're already feeling down. It's a serious block to our happiness, both now and in future. But the good news is that research shows it's a habit we can break.

Learning to stop getting stuck in negative thoughts is a vital skill for a happy and fulfilling life. If we're feeling down it's helpful to be honest with ourselves and reflect on the reasons why. But research shows that over-thinking or chewing over negative thoughts for too long increases our sadness, unhappiness and pessimism. What's more it saps concentration, motivation and initiative and affects our ability to solve problems. In other words, it makes us even more stuck and unable to see a way forward.The more we get stuck the closer it takes us into a downward spiral that leads to hopeless thoughts, such as: "I'll never be any good", "I'll never find a job" or "I'll never find a partner". These can lead to loss of confidence, anxiety or even depression.A similar type of destructive and negative, self-focused thinking is comparing ourselves to others. "She's richer", "he's thinner" "he's got a bigger house", she's got a promotion" and so on. We're surrounded by images of the rich and famous, so much so we forget they're not normal. With the exaggerated stories and glossy photos we often miss the fact that the people we see as successful are often struggling with their own problems too. However successful, clever, rich or beautiful we are there will always be someone with things we don't have that we might think we need to be happy. But what's clear from scientific studies is that this this way of thinking isn't the route to happiness. So we need to learn to detox our negative thoughts.Step 1: Break the loopHere are four tactics to break the loop. They take a little bit of will power, but not too much. Find the one that works for you:

Find some distraction. If you find yourself stuck in a negative thought trap, find some upbeat distraction. Try watching a funny video, meeting up with a fun friend or doing some exercise you enjoy. It's scientifically proven that even a small burst of positive emotions can work wonders.

Say "STOP" to yourself. Refuse to keep going over your negative thoughts. Stay focused on this until you can re-direct your mind on to something more constructive.

Try a bit of reverse psychology. Allow yourself a fixed time period each day, say 20 minutes, when you will allow yourself to wallow. Pick a time when you are usually in a good frame of mind. Then at other times of the day if negative thoughts keep coming up tell yourself that you will think about it later, at the appointed time. Chances are at that time you won't want to go over it and if you do - you've limited the time you've allowed yourself.

Phone a friend. Call someone you trust and who will help you think in a different way. Be honest about how you feel but try to limit how long you talk about your troubles. Don't call people who will encourage you to wallow in your problems or bring you down further.

Write it down. Writing about the things that are going around in your mind can be really helpful in clearing your head. It helps you see your negative thoughts for what they are which makes it easier to move on from them.

Step 2: Take some actionOk, so you've got out of that negative loop. Now you need to take a quick step, however small, towards solving what's been bothering you. This could be making a list of possible solutions and putting it somewhere visible, making an appointment to get some advice, looking up options on the internet, or asking someone you know how they dealt with something similar (or if they know someone who has). Taking positive action puts you back in control.Step 3: Work out the warning signalsTo avoid this happening in future, you need to spot the things that trigger your toxic thoughts. What situations, places, people or times cause you to get stuck on negative thoughts? What can you do to change or avoid them? Are there typical themes to these thoughts? How can you notice the warning signs and stop yourself getting stuck? Try writing your thoughts on these things down.